Which of the following is a valid Lewis dot structure for the neutral compound ozone (O_3)?

• A. O–O–O with three lone pairs on each O atom
• B. O≡O–O with no lone pairs on the central O and four lone pairs on each terminal O
• C. O–O=O with two lone pairs on the central O and two lone pairs on each terminal O
• D. O=O–O with one lone pair on the central O and three lone pairs on each terminal O

Answer: (C)

Verified step by step guidance

1. Step 1: Determine the total number of valence electrons available for the ozone (O_3) molecule. Each oxygen atom has 6 valence electrons, so for three oxygen atoms, total valence electrons = 3 × 6 = 18 electrons.
2. Step 2: Draw a skeletal structure connecting the three oxygen atoms. Since ozone is a triatomic molecule, the atoms are connected linearly: O–O–O. Assign single bonds initially between the oxygen atoms, which use 2 electrons per bond.
3. Step 3: Distribute the remaining valence electrons as lone pairs to satisfy the octet rule for each oxygen atom. Remember that each oxygen atom should ideally have 8 electrons around it (including bonding and lone pairs).
4. Step 4: Consider resonance structures and formal charges to find the most stable Lewis structure. Calculate the formal charge on each oxygen atom using the formula: \(\text{Formal Charge} = \text{Valence Electrons} - \text{Nonbonding Electrons} - \frac{1}{2} \times \text{Bonding Electrons}\). The best Lewis structure minimizes formal charges and places negative charges on the more electronegative atoms.
5. Step 5: Identify the correct Lewis structure that matches the description: O–O=O with two lone pairs on the central oxygen and two lone pairs on each terminal oxygen, which satisfies the octet rule and has the lowest formal charges.